Conventionally, this type of wire saw is disclosed in patent documents 1 and 2. The conventional wire saw described in patent documents 1 and 2 has four pieces of or a pair of machining rollers extending parallel to each other along the horizontal direction, and each machining roller is rotatable about an axis thereof. A plurality of annular grooves is formed on an outer periphery of each machining roller, and a wire is wound around the machining roller along these annular grooves. The wire saw includes a conveying device that has a movable body. The movable body can be elevated or lowered such that the movable body selectively approaches or moves away from the wire extending between a pair of machining rollers arranged on an upper side. A workpiece, which is adhered to a plate, is held on the movable body.
Due to the rotation of the machining rollers, the movable body of the conveying device is moved in the machining conveying direction while the wire is moved in a circulating manner. Accordingly, the workpiece is moved toward the wire extending between the machining rollers, and the workpiece is cut into slices by the wire. Further, by moving the movable body of the conveying device such that the movable body returns in the direction opposite to the machining conveying direction after the workpiece is cut, the workpiece after cutting is moved to be away from the wire and hence, the wire is conveyed out to the outside from the inside of a circulating region where the wire is moved in a circulating manner.